dynamic variable

例句：

1. 1. The speed of the car is determined by its dynamic variable.
   汽车的速度由其动力变量决定。
2. 2. The performance of the engine depends on the dynamic variable.
   发动机的性能取决于动力变量。
3. 3. In physics, a dynamic variable is a quantity that changes over time.
   在物理学中，动力变量是一个随时间变化的量。